# Exp 14 Lab Report - Spring 2016 - Determination of the...

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Determination of the Cause of a “Fish-Kill” in the Clark Fork of theColumbia River: A Self-Directed Experiment Johnson LiuTanner ToveyLab Section #1215-002March 9, 2016
Introduction The objective of this experiment is to determine the cause of a “fish-kill” in the Clark Fork of the Columbia River in Montana. At the start of the lab each team of students will receive a water sample from the Clark Fork of the Columbia River. Each team will then analyze the water sample for the presence of Group IA and IIA metals with the addition of Cu2+and Fe3+. The purpose for determining the presence of these ions is because they contribute to the salinity, or saltiness, of the water. Furthermore, each team of students can then analyze if the saltiness of the water is directly correlated with fish-kills.Throughout this lab, students will use experimental techniques previously learned in other labs. Emission Spectroscopy and Absorption Spectroscopy will be used to assist to successfully determine the cause of the fish-kill. Emission spectroscopy is used on clear aqueous solutions to determine the presence of Group IA and IIA ions. After the determination of certain ions is made, absorptionspectroscopy will be used to determine the concentration of the ions, most predominantly Cu2+and Fe3+.To determine the present ions in the aqueous solution through emission spectroscopy a certain equation must be used.Energy=E=hcλThe equation above is a derivative of Energy=hvwhere vis then substituted in by
cλusing the equationc=The point of this equation is to calculate the wavelength, λ, which is then usedto determine which ions are present in the solution by comparing it to the graph of the intensities of the common ions.The next technique to be used is absorption spectroscopy to determine the concentrations of the ions. One way to do this is to determine where the maxoccurs, by choosing the flattest part on the curve of the graph. Another method of determining the concentration of the ions will be to create a Beer-Lambert Plot to show the correlation between concentration and absorbance.
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